European Pressure Ulcer Advisory Panel classification system24
| Grade 1 | Non-blanchable erythema of intact skin. Discoloration of the skin, warmth, oedema, induration or hardness may also be used as indicators, particularly in individuals with darker skin |
| Grade 2 | Partial thickness skin loss involving epidermis, dermis, or both. The ulcer is superficial and presents clinically as an abrasion or blister |
| Grade 3 | Full thickness skin loss involving damage to or necrosis of subcutaneous tissue that may extend down to, but not through, underlying fascia |
| Grade 4 | Extensive destruction, tissue necrosis, or damage to muscle, bone, or supporting structures with or without full thickness skin loss |